The present invention relates to a portable memory medium such as a credit card.
Because of their convenience and security, credit cards are now widely used for settling a wide variety of transactions. Usually, when a transaction is carried out using a credit card, information embossed on the credit card, i.e., customer information, is transferred onto a slip such as a receipt by means of an emboss imprinter at a shop's register, and is kept as a record of the transaction. The purchase amount is subsequently deducted automatically from the customer's bank account.
However, a credit card can be easily counterfeited, since it has a relatively simple structure. It is therefore possible to obtain someone else's customer information, to make a counterfeit credit card by embossing the information on a card, and to use the card illegally. As a result, the amount of purchase is withdrawn from a bank account designated by the information embossed on the counterfeit credit card.